Coatings for Fresh Produce

by By: Rabbi Gavriel Price

A small sign hanging above the produce in a local supermarket
reads, “Fruits and vegetables have been coated with
food-grade vegetable, petroleum, beeswax, and/or lac-resin based
wax or resin to maintain freshness… No fruits or vegetables
have been coated with animal-based wax”. The sign is the
result of efforts by citizens groups demanding disclosure of
ingredients in coatings used on fresh produce. The produce
industry, citing the impracticality of constantly changing signs
and claiming that disclosure would compromise the confidentiality
of coatings ingredients, resisted these demands. The FDA regulation that emerged in 1994 is the result of
a compromise between the two groups. Although the sign does
disclose some information, it only tells part of a much larger
story.1

The sign is not required by law to declare the additives
put in coatings, some of which raise kashrus concerns. That
doesn’t mean that coatings on fresh produce are not
acceptable. This article will present information relevant to
evaluating the kashrus of coatings. .

First, a note about where the information came from: Coatings
manufacturers, careful to guard trade secrets, are unusually
tight-lipped about the ingredients they use. Jewish law, in any
event, limits the credibility of company spokespeople, particularly
when there is no way of verifying their claims.

Reading literature written by and for people in the produce
industry is halachically similar to overhearing a
conversation, and, in some instances, is reliable according to the
parameters of maysiach l’fi tumo, which means that the
person talking is unaware of the halachic significance of
his report.2

Much of the literature comes out of government and academic
research. Coatings extend the shelf life of fresh fruit and
vegetables and, in some instances, make fruits and vegetables look
more attractive. The technology is critical to agribusiness. The
USDA has several scientists researching
and developing more effective and less expensive coatings. These
scientists, whose salary is paid for by tax dollars, consider it
part of their job to speak to the public. Food Science departments
also invest in research into coatings. The annual conference of the
Institute of Food Technologists has featured sessions discussing
progress in coatings manufacture from various materials.3

The most straightforward way of knowing what actually goes into
coatings is by reviewing the product lines of major manufacturers.
Those products typically contain two major components: the base, or
resin, which is the majority ingredient of a coating (and which are
broadly listed on the supermarket sign), and several different
additives (which are left out).

In terms of bases, shellac (the “lac-based” resin
referred to in the sign), and carnauba wax are by far the most
commonly used. Shellac is a secretion of the lac bug, which is
found in Thailand and India. Some kashrus agencies follow the
ruling of Iggeros Moshe Yoreh Deah I:24, which offers
several reasons why shellac is acceptable as a confectionary
glaze.4

Carnauba wax is formed on the leaves of the Brazilian palm tree,
from which it is mechanically removed. It is inherently
kosher.5

A sucrose-ester base is also available on the market, but sold
on a much smaller scale.6 Other likely materials include
Candellila wax, also botanical in origin, cellulose based materials
(botanical), and petroleum, which is inherently kosher. Beeswax is
also considered inherently kosher.7

Research and development of new coatings bases include whey or
casein-protein (dairy derivatives),8 wheat (chametz),9
rice-bran (kitnios), corn zein,10 acetylated
monoglyceride11 (which can be either
from a kosher vegetable or non-kosher animal source), or from a
triglyceride emulsion12 (also from
vegetable or non-kosher animal sources).13 Coatings containing
these materials are not commonly, if at all, produced
commercially.

As far as additives are concerned, information can be taken from
the industrial product labels of the coatings. These labels are
found on the coating containers in the produce packinghouses, where
coatings are actually applied to fresh produce. These labels have
ingredient declarations that list many of the additives found in
coatings. These additives help the base be evenly dispersed and
conform smoothly to the shape of the produce. Some of the additives
can be of animal, vegetable, or dairy origin.

Morpholine oleate is an additive commonly found on ingredients
labels. Morpholine is an innocuous ammonium based ingredient that
is used to raise the pH. The “oleate” suffix indicates
the presence of oleic acid, a fatty acid. Sometimes oleic acid is
used for legal reasons (it’s necessary in the presence of
morpholine) and in other applications it is an emulsifier, critical
to the production of the coating.

An emulsifier helps a material like carnauba wax mix with water.
The coating is sprayed onto fruits, which means that it must be in
a water-solution.14

Stearic acid, another fatty acid, is also commonly added to
coatings. This additive is a plasticizer, which means it increases
the flexibility and adds toughness to a coating.

Fatty acids are one of the two major components of a fat or oil.
Although some fatty acids can come from a vegetable source only,
others, like oleic and stearic acids, can come from either a
vegetable or an animal source. How do we know whether the oleic
acid that companies are using is from the vegetable source or the
animal source?

Some companies claim that they have used vegetable based oleic
acids. A chemist from a major coatings manufacturer suggested that
it is the “climate” to purchase vegetable-derived
ingredients, and, therefore, kosher consumers can rest assured that
oleic acid is from a vegetable source. On the other hand, tallow
derivatives are typically cheaper than their vegetable
counterparts.15 Although American companies do like to declare
the use of vegetable-based ingredients for the health-conscious
consumer, that possibility does not exist with fresh produce, since
no comprehensive ingredient statement is provided to the retail
consumer. One manufacturer acknowledged that additives such as
oleic or stearic acid were not necessarily from kosher sources.
When the non-kosher alternative is cheaper, and no affirmative duty
compels manufactures to declare the origin of their ingredients, it
is hard to assume that the oleic acid being used in coatings is
from a vegetable source.

Whey (dairy) and soy (kitnios) proteins are also often
used as thickeners in coatings. Apparently the presence of dairy is
not an allergen concern, nor it is an allergen concern that
manufacturers are willing to risk. Finally, the coating solution
sometimes contains alcohol (isopropanol or ethanol).16

Table I shows both the ingredients used in coatings and their
typical proportions.17

Coatings at this stage taste terrible, and are not fit even for
an animal.

The coating is sprayed onto fruits or vegetables using a method
called wet casting. After the coatings have been sprayed onto
produce, they go through a drying tunnel and the alcohol and water
evaporate. The drying tunnel operates at temperatures considerably
less than yad soledes bo, and is typically 105 degrees
Fahrenheit.18

What is left on the fruit or vegetable after drying is the base
and additives, minus the water and alcohol. The significance of
this fact is that whatever percentage a given additive is in the
original solution, that figure is approximately four to five times
that percentage of the actual coating on the fruit. In other words,
if a given ingredient would be only 1% of the coating in the
original solution, it would constitute 5% of the coating that is
actually found on the fruit.

After drying, the range of ingredient proportions in a coating,
based on the numbers cited in Table I, is:

A dried shellac or carnauba wax based coating at this stage
tastes mildly unpleasant. The presence of coatings on fresh fruits
or vegetables is so minimal that any off-taste in the actual
coating is undetectable.

Based on all of the above, if in fact the oleic acid is from a
non-kosher source, would such a coating be acceptable? There are
various reasons to be lenient. One of them is that, according to
some poskim, in a non-food product such as toothpaste, a
non-kosher ingredient such as animal-derived glycerin would be
batel b’rov. Here too carnauba wax and shellac, the
standard bases for coatings, are considered halachically to
be a non-food product. Therefore any possible non-kosher additive
would be, like the case of the toothpaste, batel
b’rov.19

A dairy protein would similarly be batel b’rov.

Ideally, it would be best to use kosher certified coatings on
fresh produce. However, since the kosher consumer and kosher
agencies have no practical way to determine what coating was used,
one should consult his or her posek.

1 The labeling law can be found in the Code of Federal
Register (CFR) 101, 21 (22)..

2 Advertisements or other literature that promote a product is
not credible.

3 The usefulness of coatings is not limited to fresh produce.
According to Dr. J.H. Han of the University of Manitoba
whey-protein (dairy) based coatings may be used on pizza between
the cheese and the crust to keep the crust crispy, and in fruit
pies to keep the fruit from softening the crust. Enrobing pecans in
butter pecan ice cream and separating caramel from chocolate in
candy bars are other possible applications for coatings.

4Minchas Yitzchak 10:65 also discusses shellac and Rav
Shlomo Shmuelevitz, Halichas ha Sadeh 109 raises possible
objections to the acceptability of shellac. A detailed discussion
of this matter is beyond the scope of this article.

5 Sometimes, stearates, which can be animal-derived, may be used
at a late stage of the processing. Carnauba wax, however, is not
considered a food item. Therefore, some poskim argue that the
presence of a stearate would be batel b’rov, nullified
in the majority, as explained at the end of this article.

6 A sucrose ester is the result of a reaction between a sucrose
molecule and several fatty acids. Those fatty acids can be either
vegetable or tallow (neveilah) derived. However, many
manufacturers, particularly in Europe and England, are avoiding
animal-based ingredients because of BSE
(a transmittable cattle disease).

12 Dr. Bob Hagenmaier, USDA, said that
a triglyceride emulsion research is being conducted at an
ARS (Agricultural Research Service) lab,
which is funded by the USDA.

13 Coatings derived primarily from animal sources are legally
approved but are not known to exist. Supermarket signs that declare
that produce is not being coated with animal-based coatings operate
with the presumption that no companies actually are using
animal-based coatings. But it is legal to market animal-based
coatings.

14 An emulsifier is an ingredient that helps ingredients that
would otherwise separate remain mixed in solution. Oil and water
mixed together would, eventually, separate if not for the presence
of an emulsifier to maintain them as a mixture. One way an
emulsifier does that is by keeping the oil molecules far apart from
each other so that they do not coalesce.

15 One recent financial market report (ICIS-LOR Market Report,
Fall, 2001, pg. 2) emphasized the same point, stating
“Industry provided inventory levels are suspected – and
generally accepted – as slanted toward tallow goods” as
opposed to vegetable based goods. The topic of the report is
tallow-derived glycerine (the other major component of fats and
oils) but tallow-derived fatty acids may also be included in this
broad assessment. Sometimes tallow-derived ingredients have to
undergo special costly testing called chick-edema testing to
guarantee that a food grade tallow-derivative is safe. But even
with that additional cost, according to an oleochemical broker the
cost of tallow would be less than vegetable.

16 Ethanol can come from wheat (chametz) and, when
produced abroad, often is. Domestic ethanol is almost always
corn-based. Ethanol ultimately evaporates from a coating in the
course of production. Although it may become absorbed into the
other ingredients through kevishah, prolonged immersion, the
corn-based ethanol would be batel b’rov. (Mishneh
Berurah 453:9).

17 The information in Tables I and II was provided by Dr. Bob
Hagenmaier, Research Scientist, USDA.

18Minchas Yitzchok 10:66 discusses a case in which a
possibly non-kosher coating was applied to a fruit which traveled
through a drying tunnel which may or may not have been yad
soledes bo (early drying tunnels were less efficient at drying
coated fruits and therefore may have reached 120 degrees or more
inside the drying tunnel). Minchas Yitzchok concludes that
if the drying tunnel is not yad soledes bo then shifshuf
gadol, rubbing well, is sufficient to remove the chashash
issur, a kashrus concern, (if a drying tunnel is yad soledes
bo then k’dei netilah, removing a thin layer, is
necessary). However, according to the Produce Marketing Association
coatings cannot come off simply by rubbing and recommends
purchasing uncoated fruit, or simply peeling fruit, for those who
want to avoid eating a coating.

19 The following considerations would address the permissibility
of a possibly non-kosher emulsifier, oleic acid:
a) Rav Tzvi Pesach Frank zt”l holds that an emulsifier
is a davar hama’amid – without it a solution
would lose its essential property of being uniform, and therefore
it is not batel. However, the emulsifier is only operating
as such in a preliminary stage of coating production—when the
carnauba wax/shellac is in water. After the coating has dried, the
water/alcohol portion evaporates and the emulsifier, which was
previously keeping the water/alcohol uniform with the
carnauba/shellac, no longer operates as an emulsifier per se.
Therefore, the stringency of Rav Tzvi Pesach Frank,
zt”l would not apply.
b) The action of the oleic acid helps to maintain something called
a micro-emulsion. One distinction between a micro-emulsion and a
standard emulsion is that the wax/oil molecules are so small and so
disparate – as a result of the emulsifier—that light
rays can actually penetrate the coating material. As a result, the
coatings are clear. A standard emulsion (such as milk) is opaque.
One can question whether the achievement of the oleic acid in
creating a clear material meant that the oleic acid’s
presence is impossible to deny and therefore not
batel—a concept known as p’ulasa
nickeres. However, since its effect was to make something
invisible rather than visible, the idea that its action is
nickeres – recognized—is not applicable.